import java.util.Scanner;

public class Test2_15 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        System.out.print("Enter x1 and y1:");
        double x1 = sc.nextDouble(), y1 = sc.nextDouble();

        System.out.print("Enter x2 and y2:");
        double x2 = sc.nextDouble(), y2 = sc.nextDouble();

        // 两点之间距离公式
        double distance = Math.pow((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2), 0.5);

        System.out.println("The distance between the two points is " + distance);
    }
}
